The present invention relates to a resin barrier device for an infusion tool. A further aspect of the present invention relates to such an infusion tool, which has a venting outlet and a ventilation line connected to the venting outlet.
Infusion tools are usually used for producing fiber composite components by means of infusion methods. In doing so, various infusion methods can be used, all of which have in common that resin is moved through a preform of dry fibers, provided in or on the infusion tool, due to a pressure difference between a resin inlet and a venting outlet of the infusion tool, until the preform is completely resin-impregnated and may be hardened. For the purposes of the present invention, the term infusion method includes both processes in which resin is sucked by a vacuum at the venting outlet from the resin inlet through the preform, as well as processes in which resin is pressed out of the resin inlet and through the preform by an overpressure, wherein the displaced air can escape through the venting outlet, as well as mixed method, in which both aforementioned method variants are combined. That is, within the meaning of the present invention, the term infusion method also includes injection methods, and the term infusion tool also includes injection tools.
In the so-called resin transfer molding (RTM) process, a preform is impregnated with a resin and hardened in a closed infusion tool. In doing so, the preform is first introduced into a hermetically sealed cavity formed between a first and a second tool part. Then, a vacuum is produced at a venting outlet connected to a vacuum device via a ventilation line. As a result, resin is sucked from a resin inlet connected to a resin source through the cavity and thus through the preform to the venting outlet until the cavity is completely filled with resin and the preform is therefore completely resin-impregnated. Alternatively or simultaneously, the resin can also be injected from the resin inlet into the cavity using an overpressure. Subsequently, hardening of the resin-impregnated preform under the influence of temperature and pressure can start.
So-called resin infusion (RI) methods differ from RTM methods primarily in that the infusion tool is not a closed tool having a hermetically sealed cavity provided between two tool parts, but is an open tool having usually only one tool part, on the surface of which the preform made of dry fibers is deposited. In order to produce a hermetically sealed atmosphere around the preform anyhow, at least the surface of the preform facing away from the tool is covered by a vacuum film, preferably the entire tool including the preform, is packaged in a vacuum bag. Subsequently, similar to the RTM method, a vacuum is produced at a venting outlet in the infusion tool, and resin from a resin inlet is consequently sucked through the preform.
As an alternative to producing a negative pressure at the venting outlet, for the infusion methods described above, it is also possible to force the resin through the preform using an overpressure at the resin inlet while the air is forced through the resin and out at the venting outlet. In either case, the resin is moved through the preform due to a pressure differential between the venting outlet and the resin inlet.